Jacquard pattern devices for circular knitting machines to produce patterns in the knit fabric are known. Various types of such jacquard pattern devices are available and have been extensively used.
One type of such jacquard pattern devices is disclosed in U.S. Pat. No. 4,604,877, owned by the assignee of this application. In this type of pattern device as installed in a circular knitting machine, knitting needles are controlled by selector jacks, which actuate the knitting needles to cause the needles to move to the knitting, tucking or welting positions. Such selector jacks are also referred to as spring jacks and are engaged with or disengaged from cam races. Therefore, each of the selector jacks can act individually and needle selection is performed by which of the selector jacks are active and inactive.
These selector jacks are resilient or springy and are disengaged from the cam races by being deflected inwardly of the needle cylinder by the pattern device such that the jacks flex. Once the pattern device releases the jacks, the jacks return to their original positions in engagement with the cam races.
While successfully operating the jacks and needles, prior pattern devices have had disadvantages and deficiencies. In such prior pattern devices, the jacks are released from their deflected position in such a manner that the jacks spring back to their original positions violently by their inherent spring force. The jacks strike the surface of the cam race with considerable force, bounce therefrom and create impact shocks in the jacks and cam surface. Such violent action and impact shock frequently cause the jacks to break or burrs to form. Such burrs may break off and lodge in the needle grooves causing malfunctions to occur. Also, the vibration of the selector jacks can interfere with accurate needle selection.